turning down the Argon for TIGging

I'm trying to conserve argon. It's $42 including tax per 150 cf bottle here in NC and I'm running thru it too fast. I've always had my flow rate
at 15 cfm like mom taught me but I'm experimenting dialing it down. I've got it down to 13 cfm now with no apparent problems. I have the cheap dial type flow gauge that came with the machine.
I should also describe my setup and welds. Dynasty 200 at 200A, 3/32 lanthanated electrode, gas lenses with #7 cup. I'm doing fillets at various angles with 3/16 throats in A500 structural steel. Using E70S-6 filler and 2 second post flow. I weld for 1.5 minutes and wait 6 minutes. I would estimate my travel speed at 1.5" per minute. (I realize a pro would probably use a bigger machine for this. I'm and owner/builder and this equipment will have to do.)
My main question is: Is it always obvious to the eye when welding if you are not using enough argon on low carbon steel?
--zeb
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Can't comment on your question, but I strongly suggest you pick up a used 251 cf oxygen owner cylinder and take it in and swap it for a 251 of argon. You may be startled to find that the filling cost is nearly the same for a 251 as it is for a 150. At least it is around here. (Seattle)
GWE
zeb wrote:

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I'm in NC. I've inquired 3 or 4 times about getting a larger cylinder and they all say the 150 is my only option. 150cf = customer owned, all the other sizes are for outfits with contracts. You make me want to ask again though.
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I just called. It's actually NC state law that customer-owned bottles not exceed 150cf.
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And they won't lease the larger bottles to you?
If they will, look at how much the cost per lease is over how much you will save in fewer refills (taking into account the different price per refill). That will let you know if it is worth it to you.
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My situation was exactly that. The lease guys were cheaper for refills, and I mean about 60% of what the owner cylinder filler was. When figured with the cost of refills and the cost of the lease, it was cheaper to lease over a 5 year span.
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zeb wrote:

If they didn't cite a specific stature that you can validate, it is almost certainly BS. Much like hydrotesting which is not a legal requirement for privately owned cylinders, only for those that fall under interstate commerce regs, not that it matters with the usual cylinder swaps.
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Pete C. wrote:

Hate to tell you but hydrotesting of privately owned cylinders IS a legal requirement. If a tank is out of hydro it legally cannot be refilled. Doesn't matter who owns it. And if it has reached the end of service life it has to be scrapped. The ONLY part that causes misunderstanding is usually the item that states that IF the cylinder is full and in service at the time the hydro date comes up it does NOT have to be emptied/used and taken for hydro testing, however once it is empty it has to pass hydro before it can legally be refilled. If you know of a place that looks the other way and fills out of date bottles and you can live with the results if a bottle fails then that's your choice.
--
Steve W.

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"Steve W." wrote:

Provide cites to the claimed law please? The only actual laws I have been able to validate are DOT and only applicable to cylinders in interstate commerce, the limit of DOT authority. Privately owned cylinders are out of their jurisdiction.
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"Pete C." wrote:

I'll take the lack of response as validation. This topic has come up before, and not once has anyone been able to provide a cite to the claimed law.
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This may or may not help. DOT regulations have the force of law under the Code of Federal Regulations and DOT enabling legislation. Be ready to do a _lot_ of reading!
The DOT can levy fines, etc. for not obeying the regs. I don't know if that qualifies as a law or not, but the fines and jail terms probably won't feel much different. :)
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John Husvar wrote:

Again, their jurisdiction is limited to interstate commerce. Privately owned cylinders not used for business do not fall under their jurisdiction.
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It could just depend on local mechanical codes. I think most areas have codes that require compliance with DOT regulations on pressure vessels. The last time I actually read them for my area, 30 years ago, they stated compliance requirements for ALL pressure vessels more than 6" in diameter, or containing pressures greater than 6 lbs. References were made to both DOT and ASME data compliance. This was in the city limits, and county restrictions could be different. I have never looked at the state laws.
Beside that, I can't imagine any supplier that would fill an out of date cylinder for liability reasons alone. Some people even insist on yearly internal inspections, because hydrostatic testing has sometimes failed to identify problem cylinders. They actually remove the valve and look inside yearly. It's a pretty save bet that everyone's insurance requires it.
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Pete C. wrote:

Try to take in a cylinder out of hydro test and see what happens, YOU will get hit with a retest charge. As SOON as you want to fill that tank it falls under DOT regulations. As does the company that is selling you tha gas or even air!
If the DOT laws regarding privately owned tanks were phony as you seem to believe then why would SCUBA, SCBA, Fire Extinguishers, even the CO2 bottles used on paint-ball guns and soda fountains have to be tested? Those are ALL privately owned cylinders and ALL have to be hydro-tested.
All are parts of the Code of Federal Regulations Title 49 Part 171-180 part 178 covers the cylinders used in most shops.
This part prescribes the manufacturing and testing specifications for packaging and containers used for the transportation of hazardous materials in commerce.
(a) Applicability. (1) The requirements of this part apply to packagings manufactured (i) To a DOT specification, regardless of country of manufacture; or (ii) To a UN standard, for packagings manufactured within the United States. For UN standard packagings manufactured outside the United States, see 173.24(d)(2) of this subchapter. For UN standard packagings for which standards are not prescribed in this part, see 178.3(b). (2) A manufacturer of a packaging subject to the requirements of this part is primarily responsible for compliance with the requirements of this part. However, any person who performs a function prescribed in this part shall perform that function in accordance with this part. (b) Specification markings. When this part requires that a packaging be marked with a DOT specification or UN standard marking, marking of the packaging with the appropriate DOT or UN markings is the certification that (1) Except as otherwise provided in this section, all requirements of the DOT specification or UN standard, including performance tests, are met; and (2) All functions performed by, or on behalf of, the person whose name or symbol appears as part of the marking conform to requirements specified in this part.
This part prescribes requirements pertaining to the maintenance, reconditioning, repair, inspection and testing of packagings, and any other function having an effect on the continuing qualification and use of a packaging under the requirements of this subchapter.
(c) Periodic requalification of cylinders. Each cylinder bearing a DOT specification marking must be requalified and marked as specified in the Requalification Table in this subpart. Each cylinder bearing a DOT special permit number must be requalified and marked in conformance with this section and the terms of the applicable special permit. No cylinder may be filled with a hazardous material and offered for transportation in commerce unless that cylinder has been successfully requalified and marked in accordance with this subpart. A cylinder may be requalified at any time during or before the month and year that the requalification is due. However, a cylinder filled before the requalification becomes due may remain in service until it is emptied. A cylinder with a specified service life may not be refilled and offered for transportation after its authorized service life has expired.
(b) Any person who performs a function prescribed in this part is considered subject to the regulations of this subchapter when that person (1) Makes any representation indicating compliance with one or more of the requirements of this part; or (2) Reintroduces into commerce a packaging that bears markings indicating compliance with this part. [Amdt. 1802, 54 FR 25032, June 12, 1989, as amended by Amdt. 1802, 56 FR 27877, June 17, 1991]
(3) Dissolved acetylene UN cylinders: Each dissolved acetylene cylinder must be requalified in accordance with ISO 10462 (IBR,see 171.7 of this subchapter). The porous mass and the shell must be requalified no sooner than 3 years, 6 months, from the date of manufacture. Thereafter, subsequent requalifications of the porous mass and shell must be performed at least once every ten years.
--
Steve W.

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"Steve W." wrote:

I haven't with any of my customer owned cylinder exchanges.

Incorrect. I can fill my tanks all I want and I am not at all under DOT regulations, nor OSHA regulations as I am not engaged in commerce.

A commercial outfit filling the cylinder would potentially fall under DOT regulations, I do not, nor do the cylinders I own.

Nope.
SCUBA cylinders are routinely tested as that is the "norm". Dive shop and resort owned and operated cylinders fall under DOT and OSHA regs as they are commercial, personally owned cylinders do not.
SCBA cylinders will be under DOT and OSHA as they are commercial.
Fire extinguisher cylinders are also commercial, at least the sizes that do get tested are.
The CO2 bottles for paintball do not get hydrotested, they get "requalified" similar to the smaller LP tanks. Requalification is inspection, but rarely ever includes hydrotesting.

Again with jurisdiction limited to cylinders in interstate commerce. Privately owned cylinders not in commercial use are not in their jurisdiction.

Read that sentence a few times. They do not have jurisdiction over non-commercial cylinders.

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Pete C. wrote:

Then you have a shop that doesn't look at the test dates OR does what many shops do and includes the hydrotesting fee in with the price as a percentage. That is what my local shop does, UNLESS you want that exact tank back, then you pay the charge.

If you mean YOU can fill them YOURSELF then you are somewhat correct, However if a cylinder fails and they can show it is out of date good luck with your insurance and liability.

Since they all end up being filled at a shop with a DOT regulated compressor they ALL fall under DOT laws.

Not using your definition.

You might want to read the actual regulations.
From friend of mine who WORKS for the DOT.
For those with CO2 cylinders: There IS an exceptions to the 2" x 2' rule.
This is where the misconception about having an E number being exempt from testing. 3E tanks have the option of only having the exception number stamped on them, instead of 3E. If the tank does have a 3E designation, many times that is ALL that will be stamped into the tank, along with the date of manufacture.
The tank MUST be stamped with a 3E number. The tank will read DOT-3E-1800, or the exemption number will specify a 3E tank, such as: DOT-E8096-1800-M1060-0899F. (M#### is Manufacturer, 0899F is Date Code)
3E tanks are ONLY chrome-moly tanks, BUT not all chrome-moly tanks are 3E.
ALSO: in order for hydro test dates to be valid, they must be STAMPED into the tank. If the tank cannot be stamped (such as a fiber wrapped HPA), the hydro test info must be stamped into a metal plate, which is attached to the tank.
The ONLY exception listed is for Fire Extinguisher tanks, meaning designed, and USED as a fire extinguisher. Those are allowed pressure sensitive sticky labels.
Fiber wrapped tanks must have the test tag located near the original manufacturer's sticker, and be coated in clear epoxy to affix it to the tank.
The test date stamp for should look something like this for tester RIN# A123:
A 1 9 05 X 3 2
The RIN is stamped in a square, with each character moving clockwise. this is supposed to be stamped between the month and year of retest, in this case, September 2005.
The X is a special character and is changed, depending on what test was done. *10yr volumetric expansion test is a 5 point star. *10% overfill test is a '+' *Proof Pressure test is an 'S' *5yr external visual inspection is an 'E'
Prior Retest dates ARE NOT legal to remove unless all of the following conditions are met: 1: There is no further room for retest dates to be added: 2: The original manufacturing test date is not removed. 3: The owner's permission is obtained FIRST. 4: Minimum sidewall thickness is maintained (for metal cylinders)
The re-test date cannot be stamped into the sidewall of the tank, unless permitted by the ORIGINAL tank specification. 3E cylinders do allow for this.
I realize that there is a small list of 5-10 common Exemption numbers posted all over the web, but there are over 10,000 exemption numbers assigned.
If your tank has an exception number for ANY reason, you should look it up online to find out what it affects. Your Cylinder Exemption Number can be found here:DOT HAZMAT Exemptions Index
You can find authorized DOT retesters here: Authorized DOT Hydro Testers
FYI: The E8096 exemption is for Scott High Pressure Equipment, and is specified for NON-Standard sized 3E cylinders. They manufacture 3E compliant tanks that do not fall under the 2" x 2' rule
9 CFR 180.209 Table 1. - Requalification of Cylinders Specification for cylinder - Minimum test pressure (psig) 2 - Requalification period (years) 3 - 3000 psig - 5yr 3A, 3AA - 5/3 times service pressure, except noncorrosive service - 5, 10, or 12yr 3AL - 5/3 times service pressure - 5 or 12yr 3AX, 3AAX - 5/3 times service pressure - 5yr 3B, 3BN - 2 times service pressure - 5 or 10yr 3E - Test not required 3HT - 5/3 times service pressure - 3yr 3T - 5/3 times service pressure 5 4AA480 - 2 times service pressure - 5 or 10yr 4B, 4BA, 4BW, 4B-240ET - 2 times service pressure, except non-corrosive service - 5, 10, or 12yr 4D, 4DA, 4DS - 2 times service - 5yr 4E - 2 times service pressure, except non-corrosive (see 180.209(g) ) 5 4L - Test not required 8, 8AL - test at service pressure - 10 or 20 yr Exemption cylinder - See current exemption - See current exemption Foreign cylinder - As marked on cylinder, but not less than 5/3 of any service or working pressure marking - yr
Any cylinder not exceeding 2 inches outside diameter and less than 2 feet in length is excepted from volumetric expansion test.
NOTE: 49 CFR 180.209 does not say ONLY tanks adhering to this rule are exempt. It says tanks that meet the 2 x 2 rule are INCLUDED in the testing exemption.
Federal law provides for civil penalties up to $27,000.00 for violations of the Hazardous Materials regulations. Willful violation could result in a $250,000.00 fine and prison.

ANY cylinder that is being refilled for money IS a commercial cylinder. If it has a DOT number it is a commercial cylinder. If it is being transported in ANY way it falls under DOT regs.

Believe what you like. I just hope that you don't have a cylinder fail and find out the hard way.
Best of luck to you.
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SCUBA tanks are a duck of a different color. I was first certified in 1969. I do know something about these rules. Yes, privately owned scuba tanks do not fall under DOT regs unless they have a failure and cause injury or more than $250 damage to any vehicle or public road, are seen by a DOT employee being transported in an unsafe manner, or filled beyond 80% capacity over public roads. Then, retroactively, they are under DOT rules. So, if all goes well, nothing happens with out of date scuba tanks. The scuba tank police have a small office somewhere in Kansas with a sign on the front door that says, "OPEN TOMORROW".
Now, to get a scuba tank refilled, it must be in hydro. And the person having it filled must be a certified diver. Technically and legally. There are Mickey Mouse operators, and those Mexican and Carribean dive shops that do not adhere to those rules, but here in the US, a fill station cert can be pulled by any DOT personnel in person and pulled off the wall if they witness the filling of an out of hydro tank or not checking certification of the diver. Catastrpphic tank failures of out of hydro tanks are agressively investigated.
Comments about DOT and OSHA and people not having to do certain things because they have "personal cylinders" are empty stupid statements, as stupid as saying you can go get your welding tanks filled any old way you want them, hydroed or not. You can drive an unlicensed car on the street, too. It' s just that there's a price to be paid if caught. But YES, YES, YES, you CAN drive it on the street. And YES, YES, YES, you can get tanks filled in violation of the law.
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Pittman Pirate wrote:

I and many other divers have my own compressor. Neither my tanks, my compressor or I fall under DOT or OSHA jurisdiction. As for the bit about having to be a certified diver to have a tank filled, once again that is urban legend, as that is a dive industry standard, not a law. And having to be in hydro to be filled only applies to commercial fill stations.

No, I can fill my tanks independent of those laws because they do not have jurisdiction over me, my private cylinders or what I do with them non-commercially.
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It's ok. They're "private cylinders". ;-)
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How often are you refilling your 150?
Call all your local gas suppliers, and ask if they will "RENT" you a larger cylinder by the month. Terminology is important, don't confuse things with the words buy or lease. All the gas suppliers around me like to RENT the large cylinders for $5 to $9 a month. Some do RENT by the year, and give you one or two free months for the single payment.
You usually have to fill out a credit app and maintain OPEN account status with them to qualify for cylinder rental programs, but that can be handy as well. But they will often lease or sell certain sized cylinders to even cash customers, but it's not the big cylinders.
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